1. http://wiki.piug.org/pages/viewpage.action?pageId=34439448.
2. An Overview of International Patents;Global Patent Sources,2007
3. https://www.fiz-karlsruhe.de/de/aktuelles/news-2013.html, “Von Data Mining zu Trend Mining”, 12/09/2013.
4. http://www.rsc.org/images/Brian-Larner_tcm18-232880.pdf, slide 20.
5. http://www.wipo.int/edocs/mdocs/mdocs/en/wipo_ip_mnl_13/wipo_ip_mnl_13_5.pdf, slide 9.